Results Summary

What was the research about?

Comparative effectiveness research compares two or more treatments to see which one works better for certain patients. This research may include randomized controlled trials, or RCTs, in which researchers assign patients to one of the treatments by chance.

A patient may enroll in an RCT when, based on current knowledge of that patient’s traits, the treatments being tested have about the same chance of helping. If one treatment is known to have a better chance of helping a patient, then the patient would not enroll and would receive that treatment from the doctor.

Sometimes there isn’t enough research to show if one treatment has a better chance of helping than another. In this case, researchers may use computer programs. The programs estimate how well different treatments work in patients with certain traits. For example, a person’s age and pain level may affect how much a treatment helps.

These programs would be useful for patients with knee osteoarthritis. Not many RCTs have compared total knee replacement surgery with other treatments such as medicine or physical therapy.

In this study, the research team made a computer program for patients with knee osteoarthritis. It uses data from electronic health records. The program could help identify patients for whom

  • The treatments in the study have about the same chance of helping. These patients may wish to take part in an RCT.
  • A certain treatment may help more than another. These patients could choose that treatment.

The research team also made an online system based on the program for patients and doctors to use during a visit. Doctors can use the results from the system to talk with patients about treatment. If appropriate, they could talk about taking part in an RCT.

What were the results?

The program is useful to estimate how well treatments work in patients with certain traits.

For one year after treatment, the program estimates

  • How much pain a patient is likely to have
  • How well a patient is likely to function, such as how well they can walk

What did the research team do?

To make the program, the research team needed information about the long-term effects of total knee replacement and nonsurgical treatments. The team used information from 1,322 patients with knee osteoarthritis. Some patients had a total knee replacement. Other patients had nonsurgical treatments. The information came from four databases. The databases had survey information about patients’ pain and function one year after treatment.

The research team paired each total knee replacement patient in the databases with a patient who didn’t have surgery. The paired patients had similar traits, like similar ages, health problems, and pain before treatment. This pairing let the team compare results in similar patients who had different treatments. The team used information from the paired patients to make and test the computer program. They wanted to see how well the program could use information on patients’ traits to figure out if a certain treatment may help more than another. Then, the team made an online system for doctors and patients.

During the study, the team worked with a group of knee osteoarthritis researchers, patients, doctors, and patient advocates. The group gave input on research questions and study design.

What were the limits of the study?

Differences in the databases made it hard to pair patients who had surgery with similar patients who had nonsurgical treatment. This may have affected how well the computer program was able to estimate treatment results for patients.

The information on how well patients function after treatment came from a survey on overall physical function. A survey that asked specifically about patients’ knee function, separate from pain, may have helped the research team better predict knee function.

Future research could use newer ways to analyze information from patients. Researchers could also use information from more patients. Such research may help researchers make programs that better estimate treatment results.

How can people use the results?

The computer program could help doctors identify patients with knee osteoarthritis who, based on their traits, could take part in an RCT. The program may also help doctors identify patients who may get more, or less, benefit from a certain treatment.

Final Research Report

View this project's final research report.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments.

Peer review identified the following strengths and limitations in the report:

  • The reviewers were impressed with the quality of the report and the interesting subject of this methods development study.
  • The reviewers questioned the 1:1 matching approach to create a dataset of matched patients with total knee replacement (TKR) and patients who chose medical therapy instead. The authors acknowledged that this matching approach could limit generalizability, as the medical therapy (non-TKR) patients were chosen to match the TKR patients, and not to provide a representative sample. But the authors noted that this approach reduces the effect of variables that influence choice of therapy and, independently, the outcome of therapy.

Conflict of Interest Disclosures

Project Information

Harry P. Selker, MD, MSPH
Tufts Medical Center
$1,119,941 *
A Method for Patient-Centered Enrollment in Comparative Effectiveness Trials: Mathematical Equipoise

Key Dates

December 2013
July 2018

Study Registration Information

Final Research Report

View this project's final research report.


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Last updated: January 20, 2023